log4net修改数据库连接字符串和写自定义信息

最近项目需要用log4net来写日志，因为整个平台式在sharepoint上，我们需要记录具体是哪个子站点发生的日志，因此需要再原来的log表里面添加一个自定义信息列。由于平台的安全性要求，我们需要对连接字符串加密。连接字符串的信息是在AdoNetAppender读取的，所以我们要扩展该类。而自定义消息我们需要扩展PatternLayout类。其实有关log4net的介绍网上已经很多了，如log4net.dll使用

具体的代码如下：

  #region Log helper

    public class LogMessage

    {

        public string CustomMessage { get; set; }

        public string Message { get; set; }

        public override string ToString()

        {

            return Message;

        }

    }

    internal class CustomMessageConverter : PatternLayoutConverter

    {

        protected override void Convert(TextWriter writer, log4net.Core.LoggingEvent loggingEvent)

        {

            var logMessage = loggingEvent.MessageObject as LogMessage;

            if (logMessage != null)

            {

                writer.Write(logMessage.CustomMessage);

            }

        }

    }

    internal class CustomLayout : PatternLayout

    {

        public CustomLayout()

        {

            this.AddConverter("CustomMessage", typeof(CustomMessageConverter));

        }

    }

    public class CustAdoNetAppender : AdoNetAppender

    {

        string _connectiongStr = string.Empty;

        public new string ConnectionString

        {

            set

            {

                _connectiongStr = value;

                base.ConnectionString = _connectiongStr;

            }

            get

            {

                return base.ConnectionString;

            }

        }

    }

    #endregion

配置代码

<?xml version="1.0" encoding="utf-8" ?>

<configuration>

  <configSections>

    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net"/>

  </configSections>

  <log4net>

    <logger name="MyLogger">

      <level value="ALL"></level>

      <appender-ref ref="ADONetAppender"></appender-ref>

    </logger>

    <!--记录日志到数据库-->

    <appender name="ADONetAppender" type="ConsoleApp.CustAdoNetAppender">

      <bufferSize value="100" />

      <connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=1.0.3300.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />

      <connectionString value="data source=.;initial catalog=test;integrated security=false;persist security info=True;User ID=sa;Password=xxx" />

        <commandText value="INSERT INTO Log ([Date],[Thread],[Level],[Logger],[Message],[CustomMessage]) VALUES (@log_date, @thread, @log_level, @logger, @message,@customMessage)" />

      <parameter>

        <parameterName value="@log_date" />

        <dbType value="DateTime" />

        <layout type="log4net.Layout.RawTimeStampLayout" />

      </parameter>

      <parameter>

        <parameterName value="@thread" />

        <dbType value="String" />

        <size value="255" />

        <layout type="log4net.Layout.PatternLayout">

          <conversionPattern value="%thread" />

        </layout>

      </parameter>

      <parameter>

        <parameterName value="@log_level" />

        <dbType value="String" />

        <size value="50" />

        <layout type="log4net.Layout.PatternLayout">

          <conversionPattern value="%level" />

        </layout>

      </parameter>

      <parameter>

        <parameterName value="@logger" />

        <dbType value="String" />

        <size value="255" />

        <layout type="log4net.Layout.PatternLayout">

          <conversionPattern value="%logger" />

        </layout>

      </parameter>

      <parameter>

        <parameterName value="@message" />

        <dbType value="String" />

        <size value="4000" />

        <layout type="log4net.Layout.PatternLayout">

          <conversionPattern value="%message" />

        </layout>

      </parameter>

      <parameter>

        <parameterName value="@customMessage" />

        <dbType value="String" />

        <size value="4000" />

        <layout type="ConsoleApp.CustomLayout">

          <conversionPattern value="%CustomMessage" />

        </layout>

      </parameter>

    </appender>

  </log4net>

</configuration>

SQL脚本如下：

     CREATE TABLE [dbo].[Log] (

       [ID] [int] IDENTITY (1, 1) NOT NULL ,

       [Date] [datetime] NOT NULL ,

       [Thread] [varchar] (255) NOT NULL ,

       [Level] [varchar] (20) NOT NULL ,

       [Logger] [varchar] (255) NOT NULL ,

       [Message] [varchar] (4000) NOT NULL ,

       [CustomMessage] VARCHAR(max) NULL

     ) ON [PRIMARY]

在AssemblyInfo.cs文件中添加一句

[assembly: log4net.Config.DOMConfigurator(ConfigFile = "Log4Net.xml", Watch = true)]

调用代码：

ILog log = LogManager.GetLogger("MyLogger");
            log.Info(new LogMessage { Message = "message", CustomMessage = "cust" });

运行结果：